php - MYSQL INNER JOINS -

i have 2 tables in database. 1 used booking selection of dates , times available , other used returning selection of dates , times available. need link these 2 on 1 page.

<?php {     mysql_connect("localhost" , "" , "") or die (mysql_error());     mysql_select_db("") or die(mysql_error());       $pid=intval($_session["user_id"]);     $query = "select t1.*, t2.return_time, t2.return_date returnout t1 inner join return t2 on t1.book_time=t2.book_time";      //executes query on database     $result = mysql_query ($query) or die ("didn't query");      //this selects results rows     $num = mysql_num_rows ($result);          $dates_and_times = array();     while($row=mysql_fetch_assoc($result))     {         $dates_and_times[] = $row['book_date'].' '.$row['book_time'];         $dates_and_times[] = $row['return_date'].' '.$row['retun_time'];     } } ?>               <form method="post" action="booked.php">     <strong>dates available</strong>                 <select id="date" name="date">                           <option value="0">--select date--</option>     <?php  foreach ($dates_and_times $app_date) { ?>         <option value="<?php echo $app_date; ?>"><?php echo $app_date; ?></option>     <?php } ?>     </select> 

so need have 2 forms, 1 displaying dates , times booking , other returning. have gone wrong somewhere inner joins. ideas?

thanks!